iPhone 3G iOS4: How do I stop all Internet through my mobile network whilst abroad?

When abroad I am bored of constantly recieving huge bills from my mobile network company, even when I don't use the Internet as I'm still getting notifications from things such as Facebook and my e-mail.

However, I still want to be able to access the Internet via Wi-fi.

If I go onto
Settings > General > Network
and turn:
'Enable 3G' off
'Mobile Data' off
'Data Roaming' off

As well as turning all my notifications off and changing my 'Fetch New Data' on Mail to off should this stop me from getting any large bills but still allow me to use the Internet in Wi-Fi hotspots?

Thank you

If you turn off 3g,mobile data and data roaming you are fine you will still be able to use wifi.